In order to determine prevalence of Epstein-Barr virus (EBV) infection in salivary lymphoepitheliomas which are characaterized by the histology of undifferentiated carcinoma cells with lymphoid stroma and the high incidence among the Mongolid people, we collected cases of this type of carcinomas from different sites of China and examined them by immunohistochemical, insitu hybridization (ISH) and polymerase chain reaction (PCR) techniques.Materials & Methods : Salivary tissue samples from patients with lymphoepitheliomas and benign lymphoepithelial lesions were collected from nine university hospitals at eight cities (Changchun, Beijing, Xi'an, Wuhan, Chengdu, Shanghai, Kunming, and Guangzhou) in China. Formalin-fixed and parafin sections were used for immunohistochemistry for epithelial and lymphocytic characterization, ISH for EBER-1, and PCR for Bam HI W region of EBV DNA.Result & Discussion : We have collected 132 cases of salivary lymphoepitheliomas (41, Shanghai ; 40, Chengdu ; 1
… More9, Guangzhou ; 10, Beijing ; 10, Wuhan ; 6, Changchun ; 3, Kunming ; 3, Xi'an) and 57 benign lympnoepithelial lesions. The high incidence in Chengdu seems to be related to frequent immigration from the Shouth-West coast in the past. The lymphoepithelioma series consisted of 66 male and 63 female patients (all the Han race ; 3, unknown) , ranging in age from 9 to 73 years (mean, 44 years ; 40% of patients were younger than 40 years) . Its occurrence in the younger generation was charaacteristic. More than half of the cases were located in parotid glands (65%) , and 25% in minor salivary glands. Carcinoma cells of salivary lymphoepitheliomas were strongly immunopositive for EMA, CA153, and UEA-I binding, indicating their duct epithelial natures. Their cytoplasm was occasionaly immunopositive for LMP-1. The nuclei showed intense signals for EBER-1 by ISH in all of the cases examined. T-cells were predominant in the stroma. Positive PCR products were also shown in most of the cases. However, no EBV signals were obtained in the benign lymphoepithelial lesions. The results suggest that EBV play an important role in pathogenesis of the Chinese salivary lymphoepitheliomas, and that lymphoepithelioma is not a malignant counterpart of the benign lymphoepithelial lesion. Less